The panic that gripped Democrats during and after President Biden’s performance in the June debate against Donald Trump didn’t come out of nowhere. In January of last year, the Radio Hour produced an episode about President Biden’s age, and the concerns that voters were already expressing. But no nationally prominent Democratic politician was willing to challenge Biden in the primaries. After the debate, Julián Castro was one of the first prominent Democrats to say that Biden should withdraw from the race, and he went on to tell MSNBC’s Alex Wagner that potential Democratic rivals and even staffers “got the message” that their careers would be “blackballed” if they challenged him. Castro—who came up as the mayor of San Antonio, and then served as President Obama’s Secretary for Housing and Urban Development—ran against Biden in the Presidential primary for the 2020 election. He talks with David Remnick about how we got here, and what the Democratic Party should have done differently.